<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
</head>
<body>
  <div id="app">
  <!--     <com-a>
          <span>good</span>
      </com-a> -->
      <alert-m>
        <com-a>
            <span>good</span>
        </com-a>
      </alert-m>
      
  </div>
  <script src="./vue.js"></script>
  <script>
      const comA = {
          template: `<span>我是局部组件 comA <slot></slot> </span>`
      }

      const alertM = {
        template: `<div><h1>error message <slot></slot> </h1></div>`
      }

    var vm = new Vue({
      el:'#app',
      data:{
      },
      methods:{
      },
      components: {
          comA,
          alertM
      }
     });
  </script>
</body>
</html>
